Open up Device Manager and open up the Disk drives section. The drive should be there initially if you see it in Explorer. But when the drive disappears from Explorer, does it also disappear from Device Manager?
Ok. There are a few possibilities, but the best case for you is that the box containing the drive has started malfunctioning. External drives are generally just ordinary desktop/laptop drives in an enclosure with a power supply and USB interface. If either of those are going bad, the drive itself may be fine.
I assume you want to recover the data on the drive? The physical drive itself is worthless, and should have been replaced long ago. The only reason to go through more advanced steps is to recover the data; otherwise just toss the whole thing.
Assuming you do want the data, the next step would be to disassemble the enclosure and extract the drive inside. Exactly how depends on the enclosure, but usually just amounts to unscrewing a bunch of things.
Once you’ve extracted the drive, you can either connect it directly to your PC via internal cabling, or get a USB to SATA adapter like this:
Now that I think about it, 15 years ago it might have been parallel ATA (big ribbon cable). You’ll want to extract the drive first to be sure.
Incidentally, file recovery software does work in some cases, but it won’t here. If the device disappears from device manager, the software has nothing to work with. Recovery software is only for when you have a flaky but at least semi-functional drive, or the filesystem has become corrupted, etc. Not for hardware failures that cause the drive to “fall off the bus”.
I’m not 100% sure it’s SATA, although I’d put odds on that given that it’s a 1 TB drive. You can get PATA/IDE adapters as well, so that’s not a problem, but you want to be sure before ordering. Or get a combo adapter like this:
Some external enclosures aren’t completely trivial to get into, since for strange economic reasons they’re often sold more cheaply than the bare drives and the manufacturers don’t want people to buy the external drives only to throw them away and use the drive internally. A beefy flathead screwdriver for prying is recommended in that case.
I suppose I should add that it’s worth trying on a different PC first, and with a different USB cable. It’s possible the problem isn’t with the external drive at all. Cables do go bad sometimes. It’s not the most probable failure mode, but it’s an easy thing to rule out.
Firewire is definitely an interesting experiment since it might bypass whatever is flaky about the USB connection. Won’t help if the PSU is on the fritz or there is some more general problem with the controller board. Probably not worth buying a Firewire cable/adapter just to test that, but maybe you can find a friend with one.
If all else fails, you could try the following: With the drive out of the enclosure, give it a firm (but not too firm) whack with the palm of your hand or a rubber mallet. The idea is that an unused drive might have become “stuck.” This technique sometimes worked for me. Should be tried only as a last resort, though.
Yes, the power supply could be issue. I had some Seagate externals that wouldn’t work with WD wallwarts, but vice versa would. Given how thick it is, it’s probably two drives, adding to the power required.
You best bet is to shuck the drive(s) and use an IDE or SATA to USB adapter. The USB interface in all externals, especially current models are prone to premature failure.9/10 times, bypassing it solves the problem.
DON’T SMACK THE DRIVE OR PUT IT IN THE FREEZER! Stiction was a possible issue with older IDE drives, but is a thing of the past with newer drive technology.
As I recall, the freezer trick had to do with the angle of the head gap. The R/W head is on an arm, and as the drive gets warm that could cause uneven expansion in the arm, changing the angle of the magnetic head gap until it was no longer close enough to the original angle the patters were recorded at. Cool the assembly so the head is back to original orientation, and you can read the drive - until it heats up again.
I imagine modern tech has created head arms that do not have a warping problem, particularly with massive capacity and tighter tolerances.